1. Field of the Invention
This invention relates to aluminum extruding machines, and relates more particularly to an aluminum tube extruding machine which is stable in use and, which can produce seamless aluminum tubes.
2. Description of the Prior Art
FIG. 1A shows an aluminum extruding machine according to the prior art, which comprises two sliding tables 34 longitudinally disposed at two opposite sides, a material carrying barrel 37 connected to the piston rods 39 of two front cylinders 38 and moved on the sliding tables 34 relative to the die holder thereof, a push member 33 connected to the piston rods 35 of two rear cylinders (not shown) and moved on the sliding tables 34, a main cylinder 36 controlled to move a center rod into the die holder to define an annular cavity for the passing of the molten aluminum from the material carrying barrel, and a cutting control cylinder 40 having a cutter fixedly secured to its piston rods and moved to cut off extruded aluminum tube. This structure of extruding machine is not stable in use because the push member tends to vibrate when it is moved to force its tubular plunger into the annular cavity inside the die holder. Because the cutter is directly fastened to the piston rod of the respective cylinder, it may vibrate while cutting. Furthermore, because the die has three slots (see FIGS. 1B and 1C), an uneven stress tends to occur during the extruding process, and the extruded aluminum tube will have a detective surface.